scribner



2Sheets-Sheet 1. r

(No Model.) G. E. SGRIBNER.

BUSY SIGNAL FOR TELEPHONE LINES. No. 560,757. Patented May 26, 189 6.

(No Model.)

2 Sheets-Sheet 2. C. E. SCRIBNER. BUSY SIGNAL FOR. TELEPHONE LINES.

N0. 560,757. Patented May 26, 1896.

' magnet connected with the line.

.anism at the substation,

UNITED STATES ATENT FFICE.

v, or SAME PLACE.

. i TO THE WESTERN USY-SlG-NAL FOR TELEPHONE-LINES.-

srEcrrIcA'rIoN forming part of Letters Patent are. 560,757, dated May '26, 1896.

Application filed August 17, 1895- Serial No. 559,625. (No model.)

To all whom it may concern.-

Be it known that 1, CHARLES E. SCRIBNER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Ilhn ois, have invented a certain new and use ful Improvement in Busy-Signals for Telephone-Lines, (Case No. 389,) of which thefollowing is a full, clear, concise, and exact de had to theaccomforming a part of this scription, reference being panying drawings, specification.

My invention is a signal foruseon party telephoneelines to indicate at each substation when the line is in use. It consists ina signal or indicator actuated by the movement of the telephone-switch or other suitable mech but controlled in its movement by an electromagnet whose excitement is determined by current in the line-circuit during the use of the line. I am aware that electromagnetic signals at different stations of a party-line have been included in the in the line during its use and thus to indicate the free or busy condition of the line; but in practice the indicator or target of such a signal must be moved through a comparatively wide range to give a suitable signal, and thus for its operation requires the expenditure of considerable ener which is not always available.

In my improved signal I make use of some part of'the telephone mechanism which ismanually actuated in the use of the telephone to operate the indicator when the latter is free to move, controlling its movement, however, by an electromagnet connected with the circuit. I am thus enabled to permit a positive motion to the signal through any desired range, while determining its movementfivith amin'imum expenditure of energy.

In a particularform of my invention the indicator is carried on a weighted pivoted lever, which tends to follow the switch-hook of the telephone as the latter rises when the receiving-telephone is removed from .it for use, but which is normally engaged by a dctent carried upon the armature of an electro- When the switch-hook rises, if the line be not already relay and thusto prevent the line-circuit, so as to be excited by current in use, the indicator isengaged by the detent and prevented from following tl1e.swit'ch in its movement; but if the line be in use when the movement of the switch-lever takes place the magnet isexcited and the indicator is releasedfron the detent and follows the switchlever in its movement and is displayed at a suitable opening in the case of the instrument.

' In a prior application, (Case 37 9,) I have shown a lock-out system for party-lines,which comprises a relay-magnet which is arranged to be excited when the receiving-telephone is taken from its switch-hook, controlling the continuity of the telephone-circuit, and a stopmagneu which'is excited only when the line is already in use, which may act to obstruct the use of the tele- My present invention is readily to this device, the stop-controlling phone. adapted magnet of the earlier invention being employed also to operate the detent controlling the indicator of the present invention.

I have shown my invention in the attached drawings, in, which Figure 1 represents th'eessential elements of the device, the manually-operated lever, the indicator, the magnet, and detent controlling the movement of the indicator. Fig. 2 shows the invention as employed in con: nection with the lock-out mechanism of my earlier application. 1 Fig. "3 is a diagram illustrating the circuitsv employed with the lockout and signaling mechanism.

In Fig. l the elements representedcomprise a pivoted lever a, which may be the telephone switch-hook, another pivoted lever Z), carrying an indicator 1), a magnet c, and the armature-lever (Z of the magnet. Lever b carries at the extremity opposite to that. on which the indicator 1) is fixed a weight b which tends to raise the indicator and withdraw it from behind the screen 6. The extremity of the lever is formed into a-catch, which engages with the detentd'authe end of the lever (2. A stud a, carried by lever a,.engages lever 1) near its pivotal point and presses the lever downward in opposition to the weight b so thatthe-indicator bis concealed behind the screen. As long. as the magnet c is not excited the lever to may be vibrated without causing the display of the indicator, since the lover I), carrying the indicator, is engaged by detent (1. hen, however, the magnet c is excited, the detent d releases the lever b and permits the weight 11 as the lever a rises, to withdraw the indicator from its concealed position.

As I have already stated, niyinvention is not limited to any particularmode of exciting-magnet 0, but I have mentioned the use of the stop-magnet of a lock-out box as a suitable motor to control the detent. Such an instrument is represented in Fig. 2.

The lock-out mechanism described in my earlier application comprises two electromagnets f and g, which I have called the stopcontrolling magnet and the relay-magnet, respectively, and a telephone-switch having peculiar contacts. The armature of magnet g carris relay-contacts which control the contiunity of thetelephone-circuit at the substation. The armature of magnet f is so placed with relation-1o that of magnet g that when magnet f is excited its armature-lever is thrown into the path of the relay-lever and prevents the movement of the-latter in response to its magnet. The leverh of the telephone-switch is provided with two switchcontacts h and h respectively. The first, h, of these is adjusted to make connection with the lever after the latter has moved through-a very slight distance. The second, 712, does not become connected with the lever until it has reached the extremity of its range of movement. Circuit from lever h to contact h is thus first closed, and circuit from lever 71 to contact IL2 is completed later, as the switch-hook rises when released from the weight of the telephone. In adapting my present invention to this lock-out mechanism the detent d is carried on the lever f of the stop-controlling magnet.

Fig. 3 is a diagram of a party-line extending to two substations, each of which is furnished with lock-out mechanism and with a lmsy-indicator. In this diagram itwill be observed that the lever h of the switch-hook is connected to earth by a conductor 1. Magnet 1 is in a branch 2 from one line conductor 33, the branch terminating in contact-point h" of the switch. Magnet f is in a similar branch 4 from the other line conductor 5, this branch being normally open at contact-sprin g It. he receiving-telephone i and transmitting-telephone t are connected in a bridge 6 of the line-circuit, whose continuity is controlled by the relay-contacts g 1 Line conductor I} is grounded at any suitable point, as at a central station, through a battery or other source of current. L ine conductor 5 may include a signal Z. For the purpose ot' tracing the operation of the indicator assume that subscriber at station A requires a connection with another telephone-line. IIe removes his receiving telephone '6 from its switch-hook, which, as it rises, closes, first, the branch 4 through conductor 1 to ground and, later, the branch 2 to the same earth connection. Vhen branch 1 becomes closed, magnet f is not excited,'since no source of current is included in the circuit which is formed through it. hen, however, the branch 2 is closed to ground through magnet g, the latter becomes magnetized and, attracting its armature, brings contact-points g g into connection and closes the bridge of the line-circuit, which includes the telephones. It will be observed that since magnet f was notexcited during the movement of the switchhook the indicator was prevented from being displayed. Assume, now, that during the use of the telephone at A the subscriber at station B should require the use of the line. He would-remove his telephone from its switchhook; but as the switch-hook in rising first closed the branch 4: to ground a current would be created from line conductor 3 through the.

existing bridge 6 at station,A to line conductor 5 and thence through magnet f. The latter magnet W011l(1.lih611 be excited. In moving its armature it would not only block the movement of the relay-lever, but would release the indicator b and permit it to be displayed as the switch-hook rose. The apparatus at station 13 isshown in this position.

The substance of my invention is defined in the following claims:

1. In combination, a switch-lever of a telephone set, an indicator adapted to be set by the movement of the lever, a detent controlling the movement of the indicator, and an clectromagnet acting upon the detent, as de scribed.

2. The combinationwith the lever of an automatic telephone-switch, of an indicator adapted to be set by the movement-of the telephone-switch, a detent adapted to engage the indicator, and an electromagnet controlling the detent, as described.

3. In a telephone-line extending to several different substations, the combination. with a manually-movable lever at each substation,

of an indicator adapted to be set by the lover, a detent arranged to engage the indicator to determine its movement, an electromagnet controlling the detent, and means for altering the magnetic condition of the electromagnet at every other substation when the telephone at one substation is brought into use, as described.

4. The combination with the lever of a telephone-switch, of a busy-indicator adapted to 'follow the lever in its movement, a detent normally engaging the indicator to prevent its movement, and an electromagnet controlling the detent, as described.

5. In combination, a telephone-line extendin g to several substations, a telephone switchlcver at each station,a busy-indicator adapted to follow the switch-lever and thus to display its signal, a detent normally engaging the indicator, an electromagnet controlling the detent, and a source of current and circuit connections adapted to cause the excitement of all the electromagnets line, as described.

6. In combination, the lever of atelephoneswitch, an indicator adapted to be set by the switch-lever in its movement, a detent arranged to engage the indicator, and an electronlagnet controlling the detent, a normally open branch of the line-circuit including the electromagnet, and switch-contacts on the telephone switch for closing the circuit through said branch, as described.

7. The combination with a metallic-circuit telephone-line connected with several substations, having its different line conductors normally separated, of a source of current connected with one line conductor; a telephone-switch at each substation, an indicator adapted to be set by the lever in its move ment, a detent engaging the indicator and an eleetromagnet controlling the detent; a

during the use of the ground branch from that line conductor with which no source of current is normally connected, including the electromagnet, switcheontacts on the telephone-switch controlling the continuity of the branch, and means for closi-n'g'a bridge between the line conductors when any telephone is brought into use, as described. a

8. The combination with the lever of a telephone-switch, of an indicator adapted to be set by the lever in its movement, and a detent for determining the movement of the indicater, the detent being carried on the stoplever of a. lock-out device, as described.

In witness whereof I hereunto subscribe my name this-12th day of July, A. D.. 1895.

CHARLES E. SORIBNER. Witnesses:

ELLA EDLER, MYRTA F. GREEN. 

